So we've heard those that now-iconic opening spiel for the last time, but how did we feel by the time 'The Diamond of the Day (Part 2)' had reached its climax? In short, we were moved, more than a little surprised and mostly satisfied.

Merlin's series finale picks up exactly where Saturday's episode left off - Arthur (Bradley James) and the knights are engaged in an epic bout with Morgana's forces, while Merlin - in full-on Emrys mode - races to the battlefront...

Looming over the scene, 'Emrys' unleashes his most powerful magic to date. Forget the much-mocked 'throwing enemies into a wall' theatrics; here, Merlin (Colin Morgan) rains down a storm of magic that devastates the enemy forces, white dragon Aithusa and even Morgana (Katie McGrath) herself.

But the battle is far from won. Impressively dark scenes follow as Merlin trawls through the littered corpses of his fallen foes and allies, while - in a lovely moment from Bradley James - Arthur realizes that Mordred (Alexander Vlahos) is stalking towards him...

We expected some sort of 'out' for Arthur's death, so to see Mordred mercilessly run him through a mere six minutes into this episode blew our mind, just a little. It's a decent shock moment, but the unexpected speed with which this scene arrives also means that actor Vlahos - who's been fantastic this series and clearly has a bright future ahead of him - gets short shrift. Mordred's death is suitably dramatic but rather abrupt.

Yes, a wounded Arthur finds the strength to stand, striking down his tortured foe, and the battle is won, but the King has sustained a serious, possibly fatal, wound...

Merlin finds his friend, limp and lifeless, and carries him away from the battleground. Then, when Arthur wakes, Merlin finally, FINALLY confesses the truth about his magic.

Now, the reveal scene itself is everything you could want. Merlin's tearful confession and Arthur's reaction - ranging from incredulity, to shock, to disbelief at his own ignorance, to anger at his friend - are perfectly judged.

Our one niggle is this - why does Merlin confess now? He's had ample chance to do it many times throughout the course of this show's run - there have been times when revealing the truth would've saved his own life or the lives of others, and yet he picks this particular moment to tell Arthur all.

Yes, they're in a tight spot and all seems lost, but isn't that always the case on this show? You're left with the feeling that the reveal happens simply because this is the final episode.

But again, all that having been said, the execution of the scene itself is faultless and having it come early in this episode at least allows time to explore Arthur's reaction in a little detail.

We do also have to question though the likelihood of Gwen (Angel Coulby) guessing the truth about Merlin at the exact moment that the young warlock chose to confess the truth to her husband. Again, why now? Gaius (Richard Wilson) may have dropped a heavy hint at the battlefront, but Gwen's been given plenty of clues about Merlin before. Her sudden revelation here feels too convenient.

Speaking of Gaius, he's helping his ward care for Arthur - and who didn't love Arthur's frantic "He's a sorcerer!" followed by his quick realisation that Gaius knew the truth all along?

Feeling betrayed, the wounded Arthur spurns Merlin's help, but a fragment of Mordred's sword, forged in Aithusa's breath, is still lodged in his chest, and time is running out...

Arthur becomes increasingly embittered as his strength fades. "You've lied to me all this time," he spits at Merlin, upon witnessing another of his servant's impressive magical displays.

But the two men discover each other anew on their final quest to an ancient isle - their reminiscence about their first encounter was a nice moment, tying the entire series together.

There are many factors to Merlin's success, but a key part of it has always been the Merlin/Arthur dynamic - everybody loves a bromance - and this final episode devotes a pleasing amount of time to their relationship.

Two men sat in the woods, talking about their feelings, might not sound like the stuff that edge-of-your-seat drama is made of, but after five years of set-up and outright teasing, this is exactly the kind of pay-off that fans needed, and it works brilliantly.

Credit though to the Merlin team for not neglecting the supporting cast either - practically everyone's favorite character gets their moment in the sun. The ever-resilient Sir Leon (Rupert Young) steps up as Gwen's right hand, and Eoin Macken shines as the cocky Gwaine has his heart broken and leads his brother-in-arms Percival (Tom Hopper) on a foolhardy quest to confront Morgana, who's now a broken woman, shrieking and throttling her henchmen like a raven-haired Darth Vader.

The sorceress captures the two knights, torturing Gwaine to death off-screen in what is undoubtedly one of the episode's darkest and most moving moments.

Merlin and Arthur finally reach their destination, but - having forced the truth out of Gwaine - Morgana is waiting for them. She's no match for Merlin though, and the wizard strikes her down with Excalibur. It's perhaps a low-key exit for Katie McGrath's villain, but no less powerful for that.

Morgana is dead, but her assault has delayed our heroes too long and, after finally acknowledging Merlin's worth, Arthur dies. His final words to his friend - "Thank you" - are perfect.

Grief-stricken, Merlin summons the Great Dragon (John Hurt), who reveals that Arthur is indeed gone - there's thankfully no cheap reversal of his demise - but that he will also rise again, when Albion's need is greatest. A dark ending then, but one tinged with hope.

You can't please all of the people all of the time and there are inevitably things about the Merlin finale - chiefly the convenience of certain plot beats - that we have issues with.

We're also not sure about that very last scene - it's clear what the writers were trying to do, but the brief snatch of Merlin in the modern day just felt a little jarring after what had come before.

But this remains a fantastic series finale - the cast, led by the superb Colin Morgan, deliver fantastic final performances, the script is admirably dark and doesn't shy away from what is a difficult ending, and the show as a whole climaxes on an emotional high.

Having watched the show from the very start, we'll certainly miss Merlin - it's been a shining beacon of Saturday night TV for the past few years. To quote John Hurt's Great Dragon, it has been a privilege to know you, young warlock.